If the words "too soon" ever could apply to a comedian, this was the day. But Stubbs had to perform.

"I didn't do jokes about it, but I did jokes around it," said Stubbs, now proprietor of Utah's Wiseguys Comedy Club and morning host at 101.5 FM "The Eagle."

He joked about the then-unknown bomber filling out the forms for a rental truck or figuring out how much fertilizer to buy.

"Some of the people in the audience were at the site, trying to get away," Stubbs said. "People wanted to laugh."

People who tell jokes for a living often step up to the line between what's funny and what's offensive. And sometimes they go over the line.

But where is that line? Many comics don't find out until they've crossed it.

"A lot of comics say there's never a line," Stubbs said. "That's fine, but that doesn't mean that it's going to work."

So sorry o When the joke doesn't work -- and people get offended -- the comic may have to apologize.

In 2011, after a tsunami ravaged the Japanese coast and knocked out a nuclear reactor, comic Gilbert Gottfried posted several jokes about the tragedy on his Twitter feed -- sparking an outrage and costing Gottfried his job voicing the spokesduck in Aflac commercials. In February, the satirical newspaper The Onion issued an apology after an Oscar-night tweet that used an extreme profanity (OK, it was the "c-word") in relation to 9-year-old Oscar nominee Quvenzhané Wallis.

"When The Onion did that, I didn't like it," Stubbs said. "I know they're kidding. I know it's a joke. But I also have an 8-year-old daughter."

Anna Neatrour, a Salt Lake City librarian and writer for the Fake AP Stylebook, a parody Twitter feed, called The Onion's tweet "definitely too far."

"What they were trying to go for is a statement on the news cycle, and the way the media turns on actresses," Neatrour said. "But there would be ways to make that point without bringing a kid into the picture. If they had a joke about Anne Hathaway killing kittens, that might have done it."

Twitter also is instantaneous -- which can obliterate that moment in the brain between "that's funny" and "ooh, maybe I shouldn't."

The Tweets that Neatrour and other "Bureau Chiefs" contribute to Fake AP Stylebook are edited before anything is posted. "It's not as unfiltered as it might be," she said.

Among comedians on Twitter, Neatrour said, "there can be some pressure to be the first to get something out. ... The news cycle is so fast, people get caught up with the idea of getting something out there right away, instead of thinking about it."

Stubbs follows a lot of comics on Twitter. "As soon as something happens, there's stuff flying left and right," he said.

Stubbs books many of those comics at his three Wiseguys clubs in West Valley City, Ogden and at Salt Lake City's Trolley Square. He said most audience members don't get offended by even the most scathing comedian, in part, because he goes to great lengths to post content warnings on the club website. But comedy fans also can familiarize themselves with a comic's work via YouTube.

In early March, Stubbs opened for the legendary Joan Rivers -- and met her backstage before the show so Rivers could lay down the ground rules.

She doesn't. The words "too soon" are not in Rivers' comic vocabulary. (A lot of others are, including the aforementioned C-word.)

"Everything is fair game," Rivers said in an interview with The Salt Lake Tribune before her March 9 appearance at Kingsbury Hall. "I've always laughed through everything." Humor helped her cope after the suicide of her husband, Edgar Rosenberg, in 1987.

"This country is so damn uptight," Rivers said, and offered three words of advice to anyone who is offended by a joke: "Oh, lighten up."